The invention relates to window lifting mechanisms used in vehicle doors, and more particularly to a sliding window glass carrier member.
Window lifting mechanisms used in the doors of automobile vehicles generally have one or several guide rails. A window glass carrier member can move in translation on each rail. The carrier member or carrier members support the window glass, optionally via an intermediate carrier member. The carrier member or members are driven to move, through a manual or motor-driven mechanism, via cables.
French patent application 2,728,008 discloses a vehicle window lifter having two front and rear guide rails, a sliding carrier member sliding on each rail. The carrier members support the window glass and are driven along the rails by a system of cables. The cables pass over direction-changing pulleys at the ends of the rails and are driven by a motor. That patent does not stipulate the shape of the rail nor the shape of the sliding carrier member.
U.S. Pat. No. 4,700,508 discloses a window lifter for the sliding glass of an automobile vehicle. This window lifter has one single rail on which a carriage, particularly constituted by two slide elements connected by a plate, slides. The slide elements are driven in translation along the rail by two cables which slide in pulleys located at the end of the rail. The rail has two flanges one of which extends parallel and the other perpendicular to the window glass. The end of each flange is folded over to form an elastic pressure strip. Clearance is provided for between the pressure strip and the corresponding flange to allow movement of the flange. The corresponding facing surfaces of a flange and pressure strip form supporting surfaces and act to guide the slide elements. In the rest state, the supporting surfaces form a small acute angle; the angle is small as the pressure strips are only there to take up play arising through wear, which is of the order of several hundredths to several tenths of a millimeter. The carriage has, for each flange, a channel with parallel walls. Each channel is supported on the rails by the support surfaces of the flanges and pressure strips. Elasticity of the flanges eliminates play, even after long periods of operation. The solution proposed in that patent is complex and notably requires particular shaping of the rail for constituting the elastic pressure strips.
Apart from the problem of wear raised in U.S. Pat. No. 4,700,508, there is the problem of mounting the window lifter rail(s) and/or the problem of the transverse force exercised by the carriage on a rail.
The window glass is mounted in two slideways provided at each side of the rail; in the case of a single rail, the window glass is secured to a carriage mounted for translatory movement on the rail, also ensuring correct orientation of the window glass. In theory, there is sufficient clearance between the window glass and the slideways to limit any force exercised by the window glass on the carriage in the plane of the window glass and perpendicular to the direction of translatory movement of the carriage. In practice, it can happen that the rail is not perfectly mounted which is reflected by an offset between the axis of translation of the window glass and the rail axis; in this case, while the carriage is moving, a force can be set up in a direction perpendicular to the rail, in the plane of the window glass. This problem can also occur when one or both slideways are incorrectly mounted.
In the case of two rails, the window glass is secured on two carriages each mounted on rails. Simultaneous movement of both carriages on the two rails ensures lateral guiding of the window glass and renders the use of slideways at both sides of the window glass superfluous. Again, incorrect mounting on the rails or the window glass on the carriages can lead to forces being exercised on the rails in a direction perpendicular to the translatory movement of the carriages and in the plane of the window glass. Thus, a lack of parallelism between the rails can be a source of forces in view of the fixed distance between the carriages; similarly, faulty securing of the carriages on the window glass can lead to transverse forces, even if the rails are parallel. The forces on a rail, in a direction perpendicular to the translatory movement of the carriage and in the plane of the window glass are a source of noise and/or a need to exercise forces higher than the normal force required to raise and lower the window glass. There is a need to resolve this new problem.
Briefly, in one embodiment of this invention, there is provided a earner member having at least one tab or tongue flexible in a direction transverse to the guide rail. The tongue enables forces exercised by the carrier member on the rail to be taken up in a direction contained in the plane of the window glass and perpendicular to be direction of translation of the cater member. The latter can consequently take up clearances originating from approximate mounting of the slideways or rails, in a single or double-lift window winding mechanism.
More precisely, the invention provides a carrier member for a vehicle window winding mechanism, having a passage for a rail along which said carrier member slides, and at least one tab or tongue applying a force to said rail in a direction perpendicular to the direction of sliding of the carrier member, and parallel to the plane of a window glass.
In one embodiment, the passage opens at one face of the carrier member, and the tongue acts on the rail in a direction parallel to said face of the carrier member.
Preferably, the carrier member has two tongues, facing each other. In this case, it is advantageous when the passage has, in the direction in which the tongues exercise their force, a dimension greater than the distance between the two tongues. It is also advantageous for the tongues to be aligned with the passage.
The invention also provides a window winding mechanism, comprising a guide rail and such a carrier member.
The passage advantageously has, in the direction in which the tongues exercise their force, a dimension close to 200% of the dimension of the rail in said direction. It is also advantageous when the carrier member has two tongues, and a distance between the two tongues in the rest condition is of the order of 80% of the rail dimension in the direction in which the tongues exercise their force.
Further characteristics and advantages of the invention will become more clear from the description which follows of some embodiments thereof provided by way of example and with reference to the attached drawings.